Cover: Cover(s) made from 1/2-inch (12.9mm) ASTM A36 steel diamond plate reinforced with ASTM A572 or A588 structural steel. Hatch sizes with reinforcing rib spans up to 24 inches shall be designed to carry a maximum load of 280 psi uniformly distributed over the entire cover. For hatch sizes with rib spans over 24 inches, the load capacity decreases linearly by 25 psi per foot. Equipped with steel flush lifting handle and 316 stainless steel hold-open arms which automatically keep the cover in its open/upright position.
Lift Assist: Open stainless steel springs for easy lifting.
Frame: 3/8-inch steel angle with steel anchors welded to frame for casting into concrete.
Hardware: Heavy duty,tamper resistant hinges with recessed stainless steel pins and lugs.
Security: In the closed position the corners of the cover shall be bolted to the frame.   
Finish: Cover, frame and skirt have hot dipped galvanized finish.
Installation: Installation shall be in accordance with the manufacturer’s instructions. The entire frame, including the seat on which the reinforcing rests, shall be supported by concrete or other material designed to support the specified loading.
Warranty: Manufacturer shall guarantee against defects in materials and workmanship for a period of five years.